The present invention relates to a method for the electronical detection of coins and separation of suitable coins from unsuitable coins and a coin detector for carrying out the method.
In automate provided with coin insertion slots false coins or non-impressed metal plates can be easily inserted into the slots in place of suitable coins. A coarse coin detection is already carried out by selection of the size of the insertion slot. This type of detection however is not effective when coins of various sizes can be used and therefore the slot has to be made for the largest coins. In order to prevent the reaction of the automate when non-allowed coins are inserted thereinto various detection devices have been developed in which a specific suitable property or size of the coin served as a criterium. Moreover, none of conventional devices of the foregoing type are reliable to prevent any false detection results with the result that good or suitable coins as well as false coins were accepted by the device. An induction-type detection has proved to be most efficient hitherto but such a detection is not always sufficient.